{"id":"CVE-2026-121941","state":"PUBLISHED","title":"libmt32emu before 2.8.4 Heap Buffer Overflow via MidiStreamParserImpl::parseSysex","description":"libmt32emu before 2.8.4 contains a heap buffer overflow vulnerability in MidiStreamParserImpl::parseSysex that allows attackers to write past a heap allocation by supplying oversized unterminated SysEx messages. Attackers can feed more than 32768 SysEx data bytes through the mt32emu_parse_stream API via MIDI files, ports, or sequencer clients to corrupt heap memory and crash the application.","publishedAt":"2026-11-04T12:31:19.851Z","updatedAt":"2026-11-04T20:18:07.407Z","severity":{"score":8.5,"label":"High","version":"4.0","vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","source":"VulnCheck"},"assigner":"VulnCheck","products":["munt libmt32emu"],"affected":[{"vendor":"munt","product":"libmt32emu","packageURL":"pkg:github/munt/munt","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThan":"2.8.4","versionType":"semver"}],"repo":"https://github.com/munt/munt"}],"references":["https://github.com/munt/munt/issues/149","https://hackmd.io/@haindpwn/munt-midistreamparser-oversized-sysex-heap-overflow","https://github.com/munt/munt/commit/1749f7fed5cdb3a9015acce076a1512b1615dc3b","https://github.com/munt/munt/blob/libmt32emu_2_8_3/mt32emu/src/MidiStreamParser.cpp#L223-L257","https://www.vulncheck.com/advisories/libmt32emu-before-2.8.4-heap-buffer-overflow-via-midistreamparserimpl-parsesysex","https://hackmd.io/@haindpwn/cve-2026-121941-munt-midistreamparser-oversized-sysex-heap-overflow"],"weaknesses":["CWE-122"],"ingestedAt":"2026-11-04T20:22:06.437Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/121xxx/CVE-2026-121941.json","commit":"0cd352eb7c92cf64a6476b53a70ff3aaac0f560c","baselineCommit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-121941","state":"PUBLISHED","datePublished":"2026-11-04T12:31:19.851Z","dateUpdated":"2026-11-04T20:18:07.407Z","assignerShortName":"VulnCheck","assignerOrgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateReserved":"2026-11-04T12:05:50.249Z"},"containers":{"cna":{"title":"libmt32emu before 2.8.4 Heap Buffer Overflow via MidiStreamParserImpl::parseSysex","descriptions":[{"lang":"en","value":"libmt32emu before 2.8.4 contains a heap buffer overflow vulnerability in MidiStreamParserImpl::parseSysex that allows attackers to write past a heap allocation by supplying oversized unterminated SysEx messages. 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